Antenna transformer



I.1111111119411 WBUSC'HBECK ETA.. 2,187,014

A ANTENNATRANSFORMER,

Filed March l2, 1938 INVENTORS WERNE BUSCA/BECK $544452/ ,V0 BAEYERATTORNEY Patented Jan. 16, 1940 f unirse srarrss PATENT ori-ics ANTENNATRANSFORMER Germany Application March l2, 1938, Serial No. 195,480 InGermany March 13, 1937 l0 Claims. (Cl. ITS- 44) The present inventioninvolves a simple adapter or matching means mounted in the open airbetween a symmetrical antenna and a unilaterally grounded cable. p

An object of vthe invention is to provide an antenna matching device ofa particularly simple formof construction.

rAnother object is to provide a particularly convenient Wave adjustmentfor a matching device which allows a water-proof closure of the entireinner structure.

It is feasible to establish a junction or transition from atwo-conductor system to a threeconductor system, or viceversa, by theaid of a conductor loop having a length of '/\/4, where X isthe length'of the operating wave, which is included in a circuit organization asshown in Figure 1. Figure 2 shows an embodiment of the invention, asapplied to the structure of Figure l, while Figure 3 shows a modicationallowing improved adjustment for matching. In Figure l the conductorloop must have exactly the length of a quarter-wave, for it is onlyunder this condiu tion that the loop asumes the nature of a rejectorcircuit looking from the signal source. I-Ience,fif an arrangement ofthis kind is to operate satisfactorily, and if exact tuning is to beinsured, it must be made extensible telescope-fashion, and thisrequirement is likely to meet with serious mechanical difficulties whereopen-air installations are dealt with, su-ch as in antenna matchingtransformers, because of the necessity of providing adequate packing toprevent the entrance of moisture, etc.

Now, according tothe present invention the said practical diiiiculty isobviated, as shown in Figure 2, by simply choosing for the loop L alength slightly over M4, while precise tuning is accomplished by theagency of a short-circuiting slide S connected between the outerconductors, the midpoint `of the slide, for the salie of sym*- metry,being at ground potential. inasmuch as the short-circuited part of theloop is Aalso in reference to the slide in a symmetric position,

nothing will be changed so far as the symmetri- V cizing or balancingeffect of the whole arrangei vment is concerned.

However, there is the advantage that the Aentire line can be designed ina perfectly water-proof manner; also, in a case where a great number ofsuch devices designed for different waves would be needed such as foundin all large-power stations, all waves could be 4covered by a singletype of mechanical construction. i v

- If the Adistance between the two conductors Reactance Xp comprises aloop having a length greater than half the lengthl of the operating wavewhich may be adjusted to the proper length by shorting slide S'. Thepoint of connection of reactance Xp is slidable over the matchingsectionM.

If the characteristic .impedance Z2 of the antenna feeder lead issubstantially higher than the characteristic impedance Z1 of the cable.it may, under certain circumstances, be advisable `to introduce betweenthe symmetricizing loop and the antenna feeder lead a transformationlength equal to M4 having a characteristic impedance 1/ Z1, Z2 u asshown in VFigure 3 and comprising conductors TT. The length of theconductors can be easily adjustedby the aid of sleeves H which are slid`able over the symmetricizing or balancing loop so as to result in thedesired free length of the transformation length for the wave used. Inthe same way, of course, the transformation section may consist of twointer-engaging sleeves so that the shiftable outer sleeve engages overthe antenna feed lead having a characteristic impedance Z2.

We claim:

l. A device for coupling together a concentric conductor feeder linehaving an outer sheath and an inner conductor and a symmetrical loadcomprising an auxiliary conductor `having one end placed adjacent theend of the feeder line and connected to said inner conductor and havingthe other end connected to the outer sheath of said feeder line, thelength of said auxiliary conductor being greater than a quarter of thelength of the longest wave with which the device is to be .opn eratedand an adjustable short-circuiting slide connecting said auxiliaryconductor and said prisingan auxiliary conductor having one end placedadjacent the end of the feeder line and connected to said innerconductor and having the other end connected to the outer sheath of saidfeeder line, the length of said auxiliary conductor being greater than aquarter of the length of the longest wave with which the device is to beoperated and an adjustable short-circuiting slide connecting saidauxiliary conductor and said sheath whereby the length of said auxiliaryconductor between said slide and said inner conductor may be adjusted toone-quarter of the length of the operating Wave, said symmetrical loadbeing connected between said sheath and said auxiliary conductor at theend of said feeder line.

3. A device for coupling together a concentric conductor feeder linehaving an outer sheath and an inner conductor and a symmetrical loadcomprising an auxiliary conductor having one end placed adjacent the endof the feeder line and connected to said inner conductor and having theother end connected tc the outer sheath of said feeder line and formingan elongated loop, the length of said conductor being greater than aquarter of the length of the longest Wave with which the device is to beoperated and an adjustable short-circuiting slide connecting saidauxiliary conductor and said sheath whereby the length of said auxiliaryconductor between said slide and said inner conductor may be adjusted toone-quarter of the length of the operating wave, said symmetrical loadbeing connected between said sheath and said auxiliary conductor at theend of said feeder line.

4. A device for coupling together a concentric conductor feeder linehaving an outer sheath and an inner conductor and a symmetrical loadcomprising an auxiliary conductor having one end placed adjacent the endof the feeder line and connected to said inner conductor and having theother end connected to the outer sheath of said feeder line and formingan elongated loop, the length of said conductor being greater than aquarter of the length of the longest wave with which the device is to beoperated and an adjustable short-circuiting slide connecting saidauxiliary conductor and said sheath whereby the length of said auxiliaryconductor between said slide and said inner conductorl may be adjustedto one-quarter of the length of the operating wave, the outer sheath ofsaid feeder line and said auxiliary conductor being extended beyond theend of said feeder line as a pair of parallel conductors and saidsymmetrical load being connected to the ends thereof.

5. A device for coupling together a concentric conductor feeder linehaving an outer sheath and an inner conductor and a symmetrical loadcomprising an auxiliary conductor having one end placed adjacent the endof the feeder line and connected to said inner conductor and having theother end connected to the outer sheath of said feeder line and formingan elongated loop, the length of said conductor being greater than aquarter of the length of the longest wave with which the device is to beoperated and an adjustable short-circuiting slide connecting saidauxiliary conductor and said sheath whereby the length of said auxiliaryconductor between said slide and said inner conductor may be adjusted toone-quarter of the length of the operating wave, the outer sheath ofsaid feeder line and said auxiliary conductor being extended beyond theend of said feeder line as a pair of parallel conductors, the distancebetween said parallel conductors being so chosen that the impedance ofthe symmetrical load is equal to that of the feeder line.

6. A device for coupling together a concentric conductor feeder linehaving an outer sheath and an inner conductor and a symmetrical loadcomprising an auxiliary conductor having one end placed adjacent the endof the feeder line and connected to said inner conductor and having theother end connected to the outer sheath of said feeder line and formingan elongated loop, the length of said conductor being greater than aquarter of the length of the longest Wave with which the device is to beoperated and an adjustable short-circuiting slide connecting saidauxiliary conductor and said sheath whereby the length of said auxiliaryconductor between said slide and said inner conductor may be adjusted toone-quarter of the length oi the operating wave, the outer sheath ofsaid feeder line and said auxiliary conductor being extended as a pairof parallel conductors beyond the end of said feeder line a distance atleast as great as half the length of the longest wave with which saiddevice is to be operated and said symmetrical load connected to the endsof said parallel conductors.

7. A device for coupling together a concentric conductor feeder linehaving an outer sheath and an inner conductor and a symmetrical loadcomprising an auxiliary conductor having one end placed adjacent the endof the feeder line and .e

connected to said inner conductor and having the other end connected tothe cuter sheath of said feeder line and forming an elongated loop, thelength of said conductor being greater than a quarter of the length ofthe longest wave with .'1.'

which the device is to be operated and an adjustable short-circuitingslide connecting said auxiliary conductor and said sheath whereby thelength of said auxiliary conductor between said slide and said innerconductor may be adjusted to one-quarter of the length of the operatingwave, the outer sheath of said feeder line and said auxiliary conductorbeing extended as a pair of parallel conductors beyond the end of saidfeeder line a distance at least as great as half the length of thelongest wave with which said device is to be operated, said symmetricalload being connected to the ends of said parallel conductors and anadjustable reactance connected across said pair of parallel conductors.

8. A device for coupling together a concentric conductor feeder linehaving an outer sheath and an inner conductor and a symmetrical loadcomprising an auxiliary conductor having one end placed adjacent the endof the feeder line and connected to said inner conductor and having theother end connected to the outer sheath of said feeder line and formingan elongated loop, the length of said conductor being greater than aquarter of the length of the longest wave with which the device is to beoperated and an adjustable short-circuiting slide connecting saidauxiliary conductor and said sheath whereby the length of said auxiliaryconductor between said slide and said inner conductor may be adjusted toone-quarter of the length of the operating Wave, the outer sheath oi'said feeder line and said auxiliary conductor being extended as a pairof parallel conductors beyond the end of said feeder line a distance atleast as great as half the length of the longest wave with which saiddevice is to be operated, said symmetrical load being connected to theends of said parallel conductors and an adjustable reactance connectedacross said pair of parallel conductors, the point of conkan innerconductor and a symmetrical load comy nection of said reactancebeingvariable along the length of said conductors.

9. A device for coupling together a concentric conductor feeder linehaving an outer sheath and an inner conductor and a symmetrical loadcomprisingan auxiliary conductor having one end placed adjacent the endof the feeder line and able short-circuiting slide connecting saidauxiliary conductor and said sheath whereby the length of said auxiliaryconductor between said slide and said'inner conductor may be adjusted toone-quarter of the length of the operating wave, the outer sheath ofsaid feeder line and said auX- iliary conductor being extended as a pairof parl allel'conductors beyond the end of said feeder line t a distanceat least as great as one-quarter of the length of the longest wave withwhich the device is to be operated, said symmetrical load beingconnected to the ends of said parallel conductors, the diameter of saidparallel conductors being so I relatedv to the spacing therebetween thatthe impedance thereof is equal to the geometric mean between theimpedance ofthe feeder line and the impedance of Y the loop and meansfor varying the effective length of said parallel conductors.

10. A device for coupling together a concentric conductor feeder linehaving an outer sheath and prising an auxiliary conductor having one endplaced adjacent the endof the feeder line and `connected `to saidinnerconductor andhaving. the

other end connected to the outer sheathy of said feeder line and formingan elongated loop, the

length of said conductor being greater than a quarter of the length ofthe longest wave with which the device is to be operated and anadjustable shortcircuiting slide connecting said auxilslide and saidinner conductor may be adjusted f to cne-quarter of the length of theoperating Wave, the outer sheath of said feeder line and said auxiliaryconductor being extended as a pair of parallel conductors beyond the endof said `feeder line a distance at least as great as onequarter of thelength of the longest wave with which the deviceisto be operated; saidsymmetrical load being connected to the ends of said parallelconductors, the diameter of said parallel conductors being so related tothe spacing therebetween that the Iimpedance thereof is kequal to thegeometric mean between the impedance of the feeder line and theimpedance of the loop and adjustable slides slidable over said sheathand said auxiliary conductor and in contact with said parallelconductors whereby theeiective length of said conductors may be varied.

HANS J AKOB RITTER VON BAEYER. WERNER BUSCHBECK.`

ia-ry conductor andl said .Sheath whereby the t length o-f saidauxiliary conductor ybetween saidk

